You can "do" most of Addis in a day or two, but Hilton is a nice place to relax for onward journeys.
I met some amazing people while I was here in Addis Ababa. The people were very friendly and excited to meet me.
People would go out of their way to help me out and give me guidance wherever I needed it just out of their kind hearts. The only bad experience that I had was at the very end when I reached the airport. I had to give up my remaining money because there is NO WAY to get the money exchanged back and they will take it at the gate if it is too much (over $10US in local currency). I feel this is NOT right to do to travelers.
There is a lot to see in Addis and envirement. Entoto-mountain, churches, musea but also just walking and talking with the people.
Great city where people are very affable and friendly. the culture is is moderately friendly. one can comfortably spend 4 to 7 days pleasantly.
Not the dirtiest city in Africa, but far from "clean." There are few things to see. One day is enough to see it all.
Don't miss Lucy at the National Museum, then get out to Ethiopia's gorgeous country and historical sites!
If I were to spend more time in Ethiopia simply for vacation, I would spend it in the smaller towns with more historical sites.
The food will be just as good, the housing will be likely as good, and both will be cheaper. Addis is like Shanghai years ago, dirty and unrefined. I saw people urinating and defecating on the sides of the streets. It is growing up, but still has a way to go.
City Center is chaotic with traffic jams, you will need to leave early to rush destinations around the city center.
Growing vibrant City who has not yet reached her full potential, but is headed in the right direction.